Halep needed just 76 minutes on the main stadium court to dispatch Wang as she won 64 percent of her first-serve points and broke Wang's serve seven times.

Halep said she is happy with the way she is playing at this stage in the tournament.

"I am confident. I am feeling the game," she said.

Halep and second seed Caroline Wozniacki have taken turns being No. 1 this year with Wozniacki grabbing it after beating Halep in three sets in the Australian Open final and Halep winning it back just prior to Indian Wells.

Halep can hold onto the top ranking by reaching the final here.

Halep won this event in 2015 and Wozniacki won it in 2011.

Wang was the last Chinese player standing in the California desert, having achieved a career best result in Indian Wells by reaching the round of 16.

Tuesday's quick victory came two days after Halep needed over two hours to eliminate American teenager Caroline Dolehide 1-6, 7-6 (7/3), 6-2.

"The previous match was really tough for my body," said Halep, who missed some time this year with a right foot injury.

"I stayed so many weeks off with injury and now coming back, so I was a little bit tired.

"I missed too many shots in the first set. And then I just got the idea of what I have to do to play against her, and it was much easier."

- Venus moves on -

Meanwhile, Williams survived a difficult fourth round test to beat Sevastova just one day after beating sister Serena for the first time since 2014 in Montreal.

Williams, who is the oldest female player in the draw at 37, rallied back in the second set to book her spot in the quarter-finals.

She next faces either wild card Danielle Collins or world number 27 Carla Suarez Navarro of Spain.

The 25-year-old Czech Pliskova blasted four aces and broke Anisimova's serve three times in the one hour, 32 minute match.

Pliskova advances to the quarter-finals where she will face Naomi Osaka of Japan who beat unseeded Maria Sakkari 6-1, 5-7, 6-1.